on both versions there is a powerpole that leans to the left which is distracting and cant be fixed well unless your really good at free transform or puppet warping.
i dare say its more a problem of using a wide angle lens close to the car which causes barrel distortion. it can be fixed using photoshop, but you can also not have the problem to begin with by choosing a more telephoto lens and moving back away from your subject more.

its mounted using a super sophisticated mount. oh wait, no its not...
ghetto, lol. bounces heaps so i just send it up taking a pic every couple of seconds and hope for the best.
working on a new single string kite so i can send it up on a picavet mount which will make it stable enough to shoot video. i shot some vid with this mount and it was unwatchable, it was bouncing around heaps.
gopros weigh stuff all so it went up easy, even on this small, cheap kids kite.

heaps of stuff on google about mounting a gopro to a helicopter...
http://www.google.com.au/search?hl=en&q=gopro+helicopter+mount
ive wanted to mount one to a helicopter for ages, but until i win lotto my $15 kite will have to do, lol

anything wrong with the two lenses you have? if your just using auto it would probably be pointless spending thousands on new lenses.
that being said, a 10-20mm or similar would be a nice addition.
as for what settings you should be using. i find that ISO 80, F8 at 30 seconds (fluro white balance) works for me. But your milage may vary.
sounds like you need to read this...
http://cameradojo.com/2011/06/13/shooting-in-manual-mode/